Petroleum resins from heavy fractions



PETROLEUM RESHNS FRUM HEAVY FRACTTUNE Glen 1?. Hamper, Baton Rouge, 1a.,assignor to Esso Research and Engineering Qonrpany, a corporation ofDelaware Application January 8, 1953, Serial No. 330,293

Claims. (Cl. 260-82) This invention relates to the production ofpetroleum resins prepared from selected steam cracked distillatefractions and to the high softening point petroleum resins producedthereby.

Unsaturated petroleum fractions have been used as feeds for preparinghydrocarbon petroleum resins. example, heavier petroleum fractions suchas naphtha, gas oil, and the like, are cracked at relatively lowpressure and at temperatures of 1000 to 1500 F. in the presence of steamand for relatively short contact times. The gas and liquid streamsproduced contain large quantities of diolefins and olefins in the C5 toCio range. The naphtha distillate streams obtained by steam crackingoperations contain large amounts of diolefins, olefins, aromatics andsome paraifins.

The resins produced from these streams, however,

have softening points that are generally too low for certainapplications, such as, for example, in floor tile compositions. For useas the binding ingredient in floor tile, for example, it is desirablethat hydrocarbon resins have softening points of about 95-100 C. orgreater so that the floor tiles made therefrom have the requiredindentation characteristics, flexibility, and impact resistance. Most ofthe resins that are produced from such hydrocarbon streams byFriedel-Crafts polymerization have softening points lower than 100 C.

It has been discovered that naphtha streams produced from low pressuresteam cracking of gas oil, naphtha, etc., contain large quantities ofvarious diolefins (-30 wt. per cent), olefins and aromatics. Thediolefins may be recovered by thermal soaking in order to dimerize theactive diolefins. It is necessary to prefractionate the naphtha. This isdone in a manner wherein the lightest boiling diolefin monomers, whenpresent as the dimers, will not boil in the boiling range of theheaviest diolefin monomers. After this thermal soaking, the dimers,codimers and trirners formed are recovered by distillation. In thisdistillation, the unreacted naphtha is taken as an overhead stream andthe dimerized products are removed as a bottoms stream. The bottomsfraction thus obtained is then fed to a cracking zone whereby thematerial is heated to a temperature (400-700 F.) above the cyclodiolefindimer cracking point. The total heated stream contains diolefins as thecyclic diolefin monomers and the non-cyclic diolefins as the dimer,codimer or higher homologs.

In order to carry out the invention, this total heated stream boilingfrom 80 to 580 F. from which polymeric and carbonaceous materials havepreviously been removed is preferably mixed with an inert solvent priorto polymerization. The stream boiling from 115 to 580 F. may also beemployed. The preferred proportions are 2 parts solvent to 1 part ofdiolefins. Inert solvents such as aromatic or paraflin hydrocarbons canbe used.

A steam cracked naphtha having a boiling range of 80 to 280 F. wasthermally soaked at 300 F. for 6-8 hours. The pressure employed was thevapor pres- 5* Patent 0 For 2,753,326 iiatented July 3, 1956 sure of theliquid at this temperature; e. g., -400 p. s. i. g. A yield of 27.1 wt.per cent dimer or codimer was formed. The dimer product was removed fromthe naphtha by distillation. Analytical data obtained on this materialare as follows:

VACUUM DISTILLATION, 3O PLATES, 10/1 REFLUX RATIO Refractive IndexGravity, API 60 F Analysis by Ultraviolet:

Cyolopentadiene .wt. percent. Methylcyclopentadiene do 1 Temperaturereadings converted to atmospheric conditions.

After cracking at 400-700 F, as above described, the mixture issubjected to a Friedel-Crafts catalyst such as BPa, AlCls, or AlBrs,whereby the diolefin monomers and dimers are polymerized to a hard,resin product which remains substantially in solution in the inertdiluent. The temperature of the polymerization may be between -20 and+200 F. The preferred limits are 0 to +100 F. The solvent plus the resinproduct and the excess catalyst is then contacted with alcohol and waterto remove the catalyst. The water-washed mixture of solvent. and resinis then fed to a fractionator to remove the solvent for recycling andthe resin product is removed as a bottoms stream which may besubsequently stripped to any desired softening point.

If desired, other materials may be added to the polymerizing mixture inorder to alter the properties of the product.

The invention will be described in greater detail by the followingexamples although it is not intended to limit the invention to the exactdetails disclosed therein.

Example 1 1 wt. per cent diolefin dimers and the other components above.To recover the dimers, stream 2 is: fed to tower B, taking overheadstream 3 and part. of this'condensate is returned through line 4 asreflux. Stream 3 contains C5, C6 and C7 fractions which are relativelyfree of t diolefins. The dimer product (Cm-C14) is removed as a bottomsstream 5. Part of this stream is returned to tower B through line 6 tofurnish heat to the tower. Stream 7 is then C10Cl4 components (C5, C0,C1 dielefin dimers or codimers) and any recycle streams 2.2 which arefed to cracking zone C. The cracking zone C is maintained at 350-900 F.,preferably 400-700 F., and 0-10 pounds pressure. Stream. 8 from the:cracking zone then contains 5060% monomers of cyclopentadiene,methylcyclopentadiene, dimethylcyclopentadiene, and other cyclicdiolefins and 40-50% uncracked dimers or codimers of isoprene,piperylene, hexadienes, heptadienes and other non-cyclic diolefins. Thismixture of diolefin monomers and dimers is fed to tower D. An overheadvapor of C5 components (68ll0 F.) is removed overhead as stream 9 andpart of the condensed stream recycled through line 10 to the top tray asreflux. wt. per cent cyclopentadiene. The tower is operated with theminimum reflux ratio (l/ 1) required to produce a greater than 90%cyclopentadiene overhead stream. It may be desirable to operate underreduced pressures to minimize any dimerization of cyclopentadienes backto the dimer without the tower. A mixture of methylcyclopentadiene,dimethylcyclopentadiene, and other cyclic diolefin monomers togetherwith the uncracked dimers are removed from the tower as bottoms stream11. Part of this stream may be recycled to the cracker by line 22. Apart of stream 11 is returned to tower D by line 21 to furnish heat tothe tower. The remainder of the stream is combined with a diluent (Cs-C7paraflins or aromatics) to form the polymerization feed stream. Thesolvent is added by line 14 to keep the resin formed in solution.Catalyst is added by line 13. The polymerization is conducted in reactorE with BF; or AlCl3 catalyst. Polymerization conditions are 10-60minutes at 0 to 100 F. for BFs catalyst 200 F. for AlCls catalyst. Thepolymerized material in solution with the solvent is passed from thereactor by line 23 and is water-washed in vessel F. Steam may be addedby line 17. Water or steam condensate with the catalyst is removedthrough line 16.

The solvent and the resin product are removed through line 15 and fed tothe second tray of tower G. Stream 24 is the solvent and unreactedportion which are taken overhead to be recycled back to thepolymerization reactor E fed by line 12. Part of stream 24 is recycledthrough line 19 as reflux to the first tray from the top of tower G. Thepolymerized product is removed as a bottoms stream 18 and may besubjected to further treatment and purification, if desired.

Example 2 A sample of uncracked dimers was blended with themethylcyclopentadiene dimethylcyclopentadiene monomer from the sameproduct. Xylene solvent was used to dilute the above blend beforepolymerization with excess BF3 gas at 4080 F. for 20-30 minutes. A yieldof 95 resin based on non-aromatic components, having a softening pointof 280 F., and an iodine number of 400, was obtained. Normally, resinshaving softening point of 200 F. and iodine numbers of 300 are obtainedwhen polymerizing such components in the presence of the originalunprocessed feed to the thermal soaker A or when treating stream 5(dimers of the various diolefins) as polymerization feed.

The unprocessed 60250 F. feed to the thermal soaker A was polymerizedwith excess BF3 gas at -40" F. for 30 minutes. A yield of 39.9 wt. percent polymeric resin was obtained having the following properties.

Softening point, F. 120 Iodine number (cg/g.) 239 Color 1 1 Gravity, API60 F. 15.9

1 1 gr. polymeric resin in 67 ml. xylene.

The naphtha feed was thermally soaked at 220 F. for 8-10 hours prior topolymerization. The naphtha containing all the dimerized diolefins(mostly cyclic (70-80%) since only thermally soaked at 20F.) waspolymerized with excess BF3 at 30-40? F. for 30 minutes.

The overhead product (stream 9) is 9095 A yield of 34.3 wt. per centpolymeric resin was obtained having the following properties.

Softening pt., F. Iodine number (cg/g.) 242 Color 1 l Gravity 14.9

1 1 gr. polymeric resin in 67 m1. xylene.

of 30 to 35 wt. per cent resin is obtained. Inspection on this resin isas follows.

Softening pt., F. 185 to 200 Iodine number to 200 Color 2 to 3 Thesedata show that a resin of lower softening point and unsaturation isformed when AlCls polymerizing the diolefins in the presence of thecracked naphthas (olefins).

Example 3 A sample of dimer concentrates (as stream 7) was cracked andcyclopentadiene removed from the cracked products by fractionation(stream 9). The bottoms containing about 24 weight per centcyclopentadiene and 53.7 weight per cent methylcyclopentadiene, alongwith other cyclic and acyclic diolefins, was then polymerized at 3540 C.using various quantities of AlCls as the catalyst. The reaction productswere washed to remove residual catalyst and then stripped to a resin(bottoms) temperature of 260 C. at 5 mm. Hg. Data relating to thesepolymerizations follow:

Resin Properties Wt. Per- Wt. Percent cent A101 Resin Soft Color IodinePt., F. Number 0. 20.5 283 9 267 1.0. 39.7 320 7 are What is claimed is:

1. An improved process for preparing petroleum hydrocarbon resins whichcomprises subjecting a cracked naphtha stream boiling from 80 to 280 F.to thermal soaking to dimerize the cyclic and non-cyclic diolefins,separating and heating the dimerized product at 400 to 700 F. wherebythe cyclic diolefin dimers are cracked to monomers and the non-cyclicdiolefin dimers remain uncracked, and polymerizing the resulting streamwith a boron fluoride catalyst at a temperature in the range between 0and 200 F. for a time between 10 and 30 minutes and isolating the resinproduced thereby.

2. An improved process for preparing a petroleum resin which comprisessubjecting a naphtha comprising cyclic diolefins, acyclic diolefins,mono-olefins, aromatics and parafiins which has been cracked at about10001500 F. to dimerization, separating a fraction in which thepolymerizable materials consist of the dimers of acyclic and cyclicdiolefins, heating said dimers at a temperature sufficient to crack thecyclic diolefin dimers to monomers, the acyclic diolefin dimersremaining uncracked, polymerizing the resulting stream with a Friedel-Crafts catalyst to produce a hydrocarbon resin, and recovering the resinproduced thereby.

3. A petroleum resin having a softening point of at least about 280 F.and an iodine number above about 400 cg./ g. produced by the process ofclaim 2.

4. Process according to claim 2 in which cyclopentadiene is removedprior to polymerization.

5. A petroleum hydrocarbon resin having a softening point of at leastabout 280 F. and an iodine number above about 400 cg./g. which has beenproduced by the process of claim 4.

References Cited in the file of this patent UNITED STATES PATENTS ThomasDec. 15, Thomas Dec. 4, Carmody Sept. 9, Soday July 4, Rowland Sept. 5,

Rowland Aug. 26,

1. AN IMPROVED PROCESS FOR PREPARING PETROLEUM HYDROCARBON RESINS WHICHCOMPRISES SUBJECTING A CRACKED NAPHTHA STREAM BOILING FROM 80 TO 280* F.TO THERMAL SOAKING TO DIMERIZE THE CYCLIC AND NON-CYCLIC DIOLEFINS,SEPARATING AND HEATING THE DIMERIZED PRODUCT AT 400 TO 700* F. WHEREBYTHE CYCLIC DIOLEFIN DIMERS ARE CRACKED TO MONOMERS AND THE NON-CYCLICDIOLEFIN DIMERS REMAIN UNCRACKED, AND POLYMERZING THE RESULTING STREAMWITH A BORON FLUORIDE CATALYST AT A TEMPERATURE IN THE RANGE BETWEEN 0AND 200* F. FOR A TIME BETWEEN 10 AND 30 MINUTES AND ISOLATING THE RESINPRODUCED THEREBY.